Meanwhile your best friend, who has yet to understand the evils of an IT band, is polishing off her weekend 12-miler without a single leg cramp. What does she know that you don’t?

A new study published in the British Journal of Sports Medicine tried to answer that by tracking the progress and stride of 249 female runners. Each of the runners struck the ground with their heels, meaning they tend to increase their risk of hurting themselves due to their heavy landing. Over the two-year period, 100 of the runners reported serious injuries, 40 or so had minor ones, and the rest ran without a painful hinge.

Now for the fun part: 21 of the runners who ran injury-free were, as the New York Timesputs it, “long-term running-injury virgins, the athletic equivalent of unicorns.” The researchers then compared their strides with those of the injured group. They found that injury-free runners “landed far more lightly than those who had been seriously hurt.”

Irene Davis, a Harvard professor who led the study, told the Times that you can put this research into action by adding more steps per minute while you’re running. Doing so will lighten the pressure you put on each foot as you land—and bring you closer to becoming a unicorn in running sneakers. —Sarah Sarway

Another way to improve your runs? Train your brain as well as your body—here’s how.